3D Computed Tomography Reconstruction Research Articles

Hip joint center lateralization minimally affects the biomechanics of patient-specific flanged acetabular components: A computational model.

Patient-specific flanged acetabular components are utilized to treat failed total hip arthroplasties with large acetabular defects. Previous clinical studies from our institution showed that these implants tend to lateralize the acetabular center of rotation. However, the clinical impact of lateralization on implant survivorship is debated. Our goal was to develop a finite element model to quantify how lateralization of the native hip center affects periprosthetic strain and implant-bone micromotion distributions in a static level gait loading condition. To build the model, we computationally created a superomedial acetabular defect in a computed tomography 3D reconstruction of a native pelvis and designed a flanged acetabular implant to address this simulated bone defect. We modeled two implants, one with ~1 cm and a second with ~2 cm of hip center lateralization. We applied the maximum hip contact force and corresponding abductor force observed during level gait. The resulting strains were compared to bone fatigue strength (0.3% strain) and the micromotions were compared to the threshold for bone ingrowth (20 µm). Overall, the model demonstrated that the additional lateralization only slightly increased the area of bone at risk of failure and decreased the areas compatible with bone ingrowth. This computational study of patient-specific acetabular implants establishes the utility of our modeling approach. Further refinement will yield a model that can explore a multitude of variables and could be used to develop a biomechanically-based acetabular bone loss classification system to guide the development of patient-specific implants in the treatment of large acetabular bone defects.

Shallow trochlear groove and narrow medial trochlear width at the proximal trochlea in patients with trochlear dysplasia: Athree-dimensional computed tomography analysis.

Although the Dejour classification is the primary classification system for evaluating trochlear dysplasia, concerns have been raised about its reliability owing to its qualitative criteria and challenges associated with obtaining accurate radiographs. This study aimed to quantify trochlear dysplasia using three-dimensional (3D) computed tomography (CT) reconstruction with novel parameters related to the transepicondylar axis (TEA). Sixty patients were enrolled, including 20 with trochlear dysplasia and 40 healthy controls. The 3D CT model was generated using the Materialise Interactive Medical Image Control System software. The following six parameters were measured in eight consecutive planes at 15° intervals (planes 0-105): the distance from the TEA to the most cortical point of the lateral condyle ('LP-TEA', where LP stands for lateral peak), medial condyle ('MP-TEA', MP for medial peak)and deepest point of the trochlea ('TG-TEA', TG for trochlear groove). The distances from the medial epicondyle (MEC) to the corresponding TEA points were measured ('LP-MEC', 'MP-MEC'and 'TG-MEC'). In the dysplasia group, TG-TEA (planes 0, 15and 30) and MP-MEC (planes 0, 15and 30) were significantly greater than those in the control group (all p < 0.05 for planes of TG-TEA and MP-MEC). For type A dysplasia, LP-MEC (plane 0) was greater than that in the control group. For type B dysplasia, the MP-MEC (planes 0 and 15) and TG-TEA (planes 0 and 15) were greater than those of the control group. For type D dysplasia, MP-MEC (planes 0, 15and 30) and TG-TEA (planes 0 and 15) were elevated. The 3D CT reconstruction analysis established a reproducible method for quantifying osseous trochlear morphology. Patients with trochlear dysplasia had a shallow TG and narrow medial trochlear width at tracking angles of 0°-30°. This finding corroborates the clinical manifestations of recurrent patellar instability that occur during early flexion. Level III.

Functional knee phenotypes appear to be more suitable for the Chinese OA population compared with CPAK classification: Astudy based on 3D CT reconstruction models.

The aim of this study was to investigate the distribution of coronal plane alignment of the knee (CPAK) classification and functional knee phenotypes in a Chinese osteoarthritis (OA) population and to compare different lower limb alignment targets according to the distribution characteristics to find suitable total knee arthroplasty (TKA) bone cut strategies for the Chinese OA patients. The computed tomography (CT) images were retrospectively collected and the three-dimensional (3D) models were reconstructed from 434 Chinese OA patients, including 93 males and 341 females, with a mean age of 66.4 ± 9.3 years. Femoral mechanical angle (FMA), tibial mechanical angle (TMA) and mechanical hip-knee-ankle angle (mHKA) were measured on the 3D models. Arithmetic hip-knee-ankle angle (aHKA) was calculated using FMA plus TMA, and joint line obliquitywas calculated as 180 + TMA-FMA. The CPAK according to MacDessi and the functional knee phenotypes according to Hirschmann were performed. In addition, the suitable TKA bone cut strategies were explored according to the phenotypes and based on the characteristics of different alignment targets, such as mechanical alignment, anatomic alignment (AA), kinematic alignment, restricted KA (rKA) and adjusted MA (aMA). Statistical differences were determined using the independent-samples t-test or the two independent-samples Wilcoxon test, with p < 0.05 considered statistically significant. The Chinese OA population showed a varus alignment tendency (mHKA = 172.1° ± 7.2°), to which the TMA was a major contributor (TMA = 84.7° ± 4.4° vs. FMA = 91.3° ± 3.2°). The mHKA was on average 3.9° more varus than the aHKA. A total of 140 functional knee phenotypes were found and 45.6% were concentrated in VARFMA3°-NEUFMA0° to VARTMA3°-NEUTMA0°. More than 70% of patients had different FMA and TMA phenotypes. There were 92.9% of CPAK distributed in types I to IV, with type I accounting for 53.9%. The FMA phenotypes were less changed if the aMA and rKA were chosen, and the TMA phenotypes were less changed if the AA and rKA were chosen. Compared with the CPAK, the functional knee phenotypes were more suitable for the Chinese OA population with a widedistribution and a varus tendency, and it seemed more appropriate to choose aMA and rKA as TKA alignment targets for resection. Level Ⅲ.

Intrahepatic and anterior course of the inferior vena cava: CT image and 3D reconstruction of a rare anatomical variation.

The widespread use of computed tomography (CT) for diagnosing and screening abdominal conditions often reveals rare, asymptomatic anomalies. There is a wide range of documented congenital variations in the anatomy of the inferior vena cava (IVC) and hepatic veins. In this report, we detail an exceptionally unusual variant of the IVC that follows a frontward and intraliver course, terminating at the anterior section of the right atrium. To gain a deeper insight into this anomaly, we employed 3D reconstruction techniques using the software Slicer and Blender.

Evaluation of Recovery Efficacy of Inspiratory Muscle Training After Lobectomy Based on Computed Tomography 3D Reconstruction.

Progressive resistance inspiratory muscle training is the principle of inspiratory air-flow resistance loading training to restore diaphragm function, increase alveolar compliance, and further improve respiratory function. However, there is a lack of research on the effectiveness of progressive resistance inspiratory training in post-lobectomy rehabilitation and the accurate assessment of lung volumes. In this study, 79 subjects diagnosed with lung cancer and undergoing thoracoscopic lobectomy were retrospectively analyzed. The subjects were divided into a control group (n = 40) and an observation group (n =39) according to the different training modalities. The control group received conventional respiratory training. The observation group received progressive resistance inspiratory muscle training based on conventional breathing training. The primary outcome indicators were the following: lung function and lung volume. The secondary outcome indicators were the following: the number of postoperative hospital days, duration of drain retention, and incidence of postoperative pulmonary complications. Baseline data on age, sex, body mass index, smoking history, education level, underlying disease, type of pathology, lung cancer stages, surgical site, preoperative lung volume, and preoperative lung function were not statistically different between the 2 groups (P > .05). The subjects in the observation group had median (interquartile range [IQR]) lung volumes at 1 month after surgery (3.22 [3.12-3.37] L vs 3.14 [2.95-3.24] L; P = .031), median (IQR) FEV1 (2.11 [1.96-2.21] L vs 2.01 [1.81-2.12] L; P = .031), and mean ± SD peak expiratory flow (5.07 ± 0.62 L/s vs 4.66 ± 0.64 L/s; P = .005) were higher than those in the control group. The median (IQR) postoperative hospital stays (5 [4-5] d vs 5 [4-6] d; P = .030) and the median (IQR) chest drain retention times were shorter in the observation group versus the control group (74 [72-96] h vs 96 [84-96] h; P = .02). There was no significant difference in the incidence of postoperative atelectasis (5.1% vs 10.0%; P = .41) and pneumonia (7.7% vs 12.5%; P = .48). Progressive resistance inspiratory muscle training was effective in improving lung volume and lung function, and in reducing the length of hospital stay and chest drain closure time after lobectomy.

Melon and rostral muscle morphology of Gervais' beaked whale (Mesoplodon europaeus): Alternating patterns of bilateral asymmetry.

Toothed whales utilize specialized nasal structures such as the lipid-rich melon to produce sound and propagate it into the aquatic environment. Very little nasal morphology of mesoplodont beaked whales has been described in the literature, and the anatomy of the melon and associated musculature of Gervais' beaked whale (Mesoplodon europaeus) remains undescribed. Heads of three (n = 3) Gervais' beaked whales were examined in detail via dissection as well as computed tomography (CT) and magnetic resonance imaging (MRI). Two additional Gervais' beaked whale individuals (n = 2) were studied via archived CT and MRI scans. Representative transverse dissection sections of the melon were processed for polarized light imaging to verify the presence of tendons inserting into the melon tissue. Three-dimensional (3D) CT reconstructions of the melon, rostral muscles, and associated structures were performed to assess morphology and spatial relationships. In all individuals, the melon's main body demonstrated a bilaterally asymmetrical, curvilinear geometry. This curvilinear shape was defined by a pattern of alternating asymmetry in the medial rostral muscles that projected into the melon's tissue. In transverse polarized light imaging, a network of tendons originating from these asymmetrical rostral muscle projections was observed permeating the melon's lipid tissue. This curvilinear melon morphology and associated asymmetrical musculature suggest a means of lengthening the lipid pathway within a relatively short dimensional footprint. In addition, the species-specific arrangement of muscular projections suggests complex fine-tuning of the melon's geometry during echolocation. Further studies may lend additional insight into the function of this unusual melon morphology.

The Reliability of Measurements for Tibial Torsion: A Comparison of CT, MRI, Biplanar Radiography, and 3D Reconstructions With and Without Standardized Measurement Training

Background: Accurate and reliable assessment of tibial torsion is important for the identification and treatment of tibial rotation malalignment; however, the ideal rotational measurement modality and technique are controversial. This study compares rotational measurements between computed tomography (CT), magnetic resonance imaging (MRI), biplanar erect radiograph (BER) reconstructions, and three-dimensional (3D) reconstructed CT before and after standardized training of observers to evaluate the reliability of each assessment method.Methods: Eight adult cadaveric specimens underwent CT, MRI, and BER imaging. Tibial torsion was measured by three independent observers (one resident and two experienced orthopaedic surgeons) both before and after standardized measurement instruction. Reliability for inter-observer measurement was evaluated using the Intraclass Correlation Coefficient (ICC). Measurement values for CT, MRI, and BER reconstructions were compared to 3D CT reconstructions analyzed using custom software to align and measure tibial torsion (used as the reference standard).Results: Before training, there was poor inter-observer reliability for CT (ICC=0.492, p=0.014) and moderate interobserver reliability for MRI (ICC=0.633, p=0.002). There was no inter-method reliability between 3D CT and MRI for two of the three surgeons and moderate to good reliability between 3D CT and CT. After training, the interobserver reliability for CT improved to 0.536 and the inter-observer reliability for MRI improved to 0.701. The BER measurements (no observer involvement) had moderate reliability compared to the 3D CT reconstructions (ICC=0.69, p=0.026). Measurement error was 4 degrees for CT pre-training and 7 degrees post-training, and 7 degrees for MRI pre-training and 8 degrees post-training.Conclusions: A standardized training regimen for MRI measurements improved both inter-observer and intraobserver reliability. Inter-method reliability between CT, MRI, and BER compared to reference 3D CT reconstructions demonstrated that all imaging modalities are a valid means to measure tibial rotation but differ in reliability from moderate to good. When assessing tibial torsional deformities, it is important to consider these variations from true rotation and feel comfortable using them for pre-operative planning purposes.Level of Evidence: N/A for a cadaveric imaging study Key Concepts•A standardized training regimen for MRI measurements of tibial torsion significantly improved inter-observer and intra-observer reliability.•CT, MRI, and BER measurements are valid imaging modalities compared to 3D CT reference standards for measuring tibial rotation.•Established manual measurements of tibial torsion from MRI may be improved with adequate training.•Measurement error of up to 8 degrees can be seen from true tibial torsion during the imaging assessment.

Imaging Findings in Pediatric Accessory Cranial Sutures using 3D CT Reconstruction: Fracture or Rudimentary Suture.

Objective:Although accessory sutures are considered to be relatively rare, the consequences of a missed diagnosis are profound. Distinguishing between accessory sutures and cranial fractures can be difficult, especially in cases of suspected non-accidental trauma. High-resolution imaging is the best way to discern between two- and three-dimensional computerized tomography (3D CT) is considered the preferred method for evaluation. The goal of this study was to determine the impact of 3D CT scans in distinguishing between accessory sutures and cranial fractures in suspected child abuse cases in a rural community and the importance of early detection in such cases, as well as call attention to the consequences of initial misinterpretation. Materials and methods:The researchers conducted a retrospective chart review of all pediatric patients diagnosed with cranial fractures (265 in total) at University Medical Center between May 30, 2016, and May 30, 2021. Initial computed tomography (CT) scans and subsequent 3D CT scans were evaluated for each patient that fit the inclusion criteria, 13 in total. Patients were then categorized into two groups based on the final diagnosis on the radiology report: accessory cranial suture or cranial fracture. Once these patients were identified, the etiology and structural components of each were evaluated, and the key differences were highlighted. Results:Our results showed that, of the 11 cases of suspected non-accidental trauma, six were finally diagnosed with accessory sutures with the use of 3D CT scans, and of those six, four were diagnosed with cranial fractures from the initial CT scan report due to a similar presentation and asymmetric nature. Conclusion:Discerning between fracture and accessory suture is essential in evaluating pediatric patients presenting with signs ofcranial fracture due to the increased risk of misinterpretation that can lead to severe legal consequences considering that cranial suture variants may mimic intentional injury and be mistaken for child abuse, causing significant distress for patients and their families.

Multidisciplinary approach to postmortem diagnostics

BACKGROUND: The technique that allows detecting various pathologies and clearly identifying the cause of death and other associated diseases without disturbing the integrity of the skin refers to postmortem radiological diagnostics and is called virtopsy. The number of autopsies decreases worldwide, which creates the need to use alternative non-invasive methods, including virtopsy. The main method of postmortem radiology is multislice computed tomography (CT), with its advantages including high sensitivity to bone pathology. Postmortem radiological diagnostics allow supplementing the classical autopsy. This multidisciplinary approach helps visualize a wide variety of pathologies and assist the pathologist in the diagnostic search.&#x0D; AIM: To assess the possibility of applying radiological diagnostic methods in the pathological anatomical practice and features of non-invasive autopsy (virtopsy) and its differences from the classical autopsy.&#x0D; METHODS: The archival material including macro preparations of two lower limbs with tumor-like masses of unclear genesis (the upper third of the femur and the calcaneal tuber) was used. The biomaterial was previously encased in a specially treated gelatin medium, which ensured its preservation and left parts of the CT scanner intact. Multislice CT was used for radiological assessment of the preparations. From the primary CT sequences obtained, scans with the best visualization in the bone and soft tissue windows were selected, and three-dimensional (3D) reconstruction was applied. Scans and 3D reconstructions of images of tumor-like masses of the heel and thigh bones were obtained. Interpretation of the borders of the mass, characteristics of morphology and possible source of growth of the neoplasm allowed assuming a malignant nature of the tumor, suggesting its bone origin. Further histologic examination in both cases confirmed the neoplasm (osteogenic sarcoma).&#x0D; RESULTS: CT scans and 3D reconstructions of images of tumour-like masses in the heel and femur were obtained. The interpretation of the boundaries of the mass, the morphological characteristics and the possible source of growth of the neoplasm suggested a malignant nature of the tumour, suggesting a bony origin. Further histological evaluation in both cases confirmed the nature of the neoplasm (osteogenic sarcoma).&#x0D; CONCLUSIONS: The use of postmortem radiological diagnostic elements provides a sufficiently accurate verification of the nature of some pathologies. However, the absence of tissue damage and disturbances of intact topographic characteristics play not the least role in the postmortem diagnosis. In contrast to autopsy, this technique allows to return to the original appearance of the structures examined and, if necessary, start the diagnostic search anew. Moreover, specialists from other regions can be remotely involved by sending the data of CT scanning.

3D Computed Tomography vs. 2D radiography: comparison of 3D direct anthropometry with 2D norm calculations and analysis of differences in soft tissue measurements.

The aim of this study was twofold: (1) to compare soft tissue measurements of the same distances obtained from 3D computed tomography reconstructions with 2D cephalometric radiograms, (2) to compare data from 3D measurements from direct anthropometry and 2D "norms" for the facial measurements. A total of 40 Caucasian patients that had their CBCT scans for various dental and dentoskeletal reasons were enrolled in this study. All the patients had large field of view (from the forehead to the chin). The data were stored in DICOM format and imported into a software for 3D reconstructions. After 3D facial soft tissue model generation, the distances between 18 soft tissue points were measured. The 3D soft tissue analysis was performed, and the facial indices were calculated. The mean 3D values were compared with 2D measurements performed on lateral cephalograms and Arnett's and Farkas' norms. The measurements were statistically compared using Student's t-test. Assessments from 2D and 3D measurements showed no statistical difference except for the distance Pogonion (for both male and female) and Labial superius prominence (females) to the True Vertical Line in 2D /Plane in case of 3D measurements. There was a significant difference between all 3D measurements and Arnett's and anthropometric Farkas' "norms". The mean difference between Farkas' "norms" and 3D measurements was within 3 mm for 70% of measurements. According to the results, 3D soft tissue analysis allows for complete diagnostic determination. The 3D "norms" are to be verified on a greater sample.

Pycnodysostosis- A Rare Diagnosis Not to Miss

Introduction: Pycnodysostosis derived from the Greek words pycnos-density, dys-defect, ostosis-bone is a rare inherited disorder of the bone with an incidence of 1.7 per million births. It is one of the lysosomal storage disorders with a deficiency of enzyme cathepsin K. Along with a history of repeated fractures of the bones, patients with Pycnodysostosis have a short stature, dolichocephalic skull, obtuse mandibular angle, short terminal phalanx. They also have dental abnormalities such as the delayed eruption of permanent teeth, and double rows of teeth. Mild psychomotor problems were noted in a few individuals. Pycnodysostosis is diagnosed by clinical and radiological features as there is no diagnostic criterion. Skulls show open fontanels, generalized osteosclerosis, loss of the normal angle of the jaw, and hypoplasia of facial bones. Social and occupational support needed to prevent recurrent fractures. Orthopaedic and orthodontic cares are needed. Case: A non-diabetic normotensive male of 63 years presented to the medicine outpatients department (OPD) with complaints of burning type, non-radiating moderate intensity pain in the epigastric region for three months following taking of NSAIDs. He gave a history of fractures of different bones following minimal trauma since his childhood and used to take NSAIDs every now and then. He did take orthopaedic consultation for those fractures but the underlying pathophysiology was not explored. Malunion of long bones resulted in a deformed limb. The rest of his past medical history and family history was unremarkable. On clinical examination, we found the patient had short stature with proportionately short limbs. He had dysmorphic features with a large head, small facial structures, frontal and bilateral parietal bossing. Examination of the oral cavity revealed a narrow high arched palate and hypoplastic, overcrowded teeth. His digits were short and stubby. The lower limbs of the patient have angular deformities that resulted from malunion of bones from previous fracture. Haematological and biochemical investigations were normal. Chest X-ray showed multiple ribs fracture on the right side. The patient's clavicle was normal in X-ray. Both tibia and fibula showed a malunited fracture in diaphysis. Computed tomography (CT) of the skull, as well as 3D reconstruction of CT, found open fontanelles and widening of sutures (Figure). Frontal and parietal bossing was noted. There was hypoplasia of the air sinuses. CT scans showed dysplasia of the bones of the face and hands. Hypoplasia was noted in the terminal phalanx of fingers. An endoscopy of the upper gastrointestinal tract found multiple erosion around the antrum of the stomach. Considering the clinical and radiological feature diagnosis of Pycnodysostosis with NSAIDs-induced antral erosion was made. The patient and his caregivers were briefed about the diagnosis. Consultation from a multidisciplinary team was done concerning his treatment. Conclusion: It is important to diagnose Pycnodysostosis early as it allows proper planning to prevent future fractures. While assessing a patient with short stature with a history of repeated bone fracture Pycnodysostosis should be considered along with other differentials.

Preoperative Mixed-Reality Visualization of Complex Tibial Plateau Fractures and Its Benefit Compared to CT and 3D Printing.

Various studies have shown the benefit of three-dimensional (3D) computed tomography (CT) reconstruction and especially 3D printing in the treatment of tibial plateau fractures (TPFs). This study aimed to investigate whether mixed-reality visualization (MRV) using mixed-reality glasses can provide a benefit for CT and/or 3D printing in planning treatment strategies for complex TPFs. Three complex TPFs were selected for the study and processed for 3D imaging. Subsequently, the fractures were presented to specialists in trauma surgery using CT (including 3D CT reconstruction), MRV (hardware: Microsoft HoloLens 2; software: mediCAD MIXED REALITY) and 3D prints. A standardized questionnaire on fracture morphology and treatment strategy was completed after each imaging session. 23 surgeons from 7 hospitals were interviewed. A total of 69.6% (n = 16) of those had treated at least 50 TPFs. A change in fracture classification according to Schatzker was recorded in 7.1% of the cases and in 78.6% an adjustment of the ten-segment classification was observed after MRV. In addition, the intended patient positioning changed in 16.1% of the cases, the surgical approach in 33.9% and osteosynthesis in 39.3%. A total of 82.1% of the participants rated MRV as beneficial compared to CT regarding fracture morphology and treatment planning. An additional benefit of 3D printing was reported in 57.1% of the cases (five-point Likert scale). Preoperative MRV of complex TPFs leads to improved fracture understanding, better treatment strategies and a higher detection rate of fractures in posterior segments, and it thus has the potential to improve patient care and outcomes.

Superior tensile and recovery properties of hydride-dehydride elemental NiTi alloys homogenized using high-temperature sintering

Elemental powder (EP) sintering is attractive for use in fabricating the NiTi shape memory alloys due to its low cost and compositional flexibility. However, because of sintering challenges that are not adequately resolved, current EP NiTi alloys exhibit zero or trace tensile properties. In this study, a 10−4 Pa vacuum system was used to optimize the sintering of EP NiTi alloys. The unavoidable liquid phase and high-temperature sintering promoted elemental homogenization, which substantially improved the engineering properties of EP NiTi. Compared to previous studies, increasing the vacuum level caused deflagration reactions at a low temperature of 700 °C. It also rendered the materials more susceptible to macroscopic millimeter-scale defects at > 1050 °C due to the loss of the liquid phase. These problems could be avoided by optimizing the sintering process and completing high-temperature sintering at 1250 °C. High-temperature sintering promoted local elemental homogenization rather than extensive elemental migration. 3D–Computed Tomography reconstruction revealed that high-temperature sintering promoted shrinkage of the pore volumes and homogeneity of pore size distribution. This sintering process considerably improved the mechanical properties of the EP NiTi alloy. The tensile strength and related elongation were 701–763 MPa and 16.54–21.97%, respectively, and the alloy exhibited a shape memory of >90% in an 8% tensile evaluation. This optimization strategy, which integrates impurity control and the intermetallic phase sequence, promotes the practical applications of EP NiTi alloys.

Application value of computed tomography and magnetic resonance imaging three-dimensional reconstruction and digital subtraction angiography in percutaneous transhepatic cholangial drainage.

This study aims to explore the application value of computed tomography (CT) three-dimensional (3D) reconstruction, magnetic resonance imaging (MRI) 3D reconstruction, and conventional digital subtraction angiography (DSA) fluoroscopy in percutaneous transhepatic cholangial drainage (PTCD). The clinical data of 180 patients with obstructive jaundice requiring PTCD from December 2017 to December 2021 were retrospectively analyzed. Following PTCD, CT 3D reconstruction, MRI 3D reconstruction, and conventional DSA fluoroscopy were conducted, after which the surgical success rates, liver function results, and postsurgical complications were compared. The puncture accuracies under CT 3D reconstruction, MRI 3D reconstruction, and conventional DSA fluoroscopy were 90.0% (54/60), 96.7% (58/60), and 80% (48/60), respectively. The degree of jaundice and epigastric discomfort was relieved in all three groups after surgery, while a significant reduction in the levels of total bilirubin and direct bilirubin was observed relative to the levels before surgery (P < 0.05). The incidences of complications in the CT 3D reconstruction, MRI 3D reconstruction, and conventional DSA fluoroscopy groups were 6.7% (4/60), 3.3% (2/60), and 13.3% (8/60), respectively, and the differences among the three groups were statistically significant (P < 0.05). Conducting conventional enhanced CT and MRI scans in patients before surgery might be more practical than the conventional puncture method. Among the methods under study, MRI 3D reconstruction was found to be safer and more feasible than CT 3D reconstruction and conventional DSA fluoroscopy in PTCD. MRI 3D reconstruction could reduce the degree of jaundice, improve the success rate of surgery, reduce the incidence of complications due to surgery, and improve the patients' tolerance to surgery.

Total thyroidectomy for giant nodular goiter guided by pre-operative 3D computed tomography reconstruction and 3D printing: A case report.

Nodular goiter is a common clinical problem, and thyroidectomy is preferred in patients with obstructive symptoms. Thyroidectomy is a complex procedure with some common complications. Three-dimensional (3D) computed tomography (CT) reconstruction and 3D printing provide visualized 3D anatomical structure, posing an enormously valuable potential in precise surgery with optimal efficacy and minimum complications. Here, we aimed to perform a precise thyroidectomy guided by this technology. The patient was an 80-year-old woman with 10 years of goiter, 1 year of labored dyspnea, and a history of thyroid surgery 62 years ago. In addition to ultrasonography examination, CT images were obtained to construct the 3D model to identify the 3D relationship between the lesion and adjacent structures, and a 3D model of the trachea was created and printed using a 3D printer. The 3D model clearly presented the diffuse enlargement of the two lobes and isthmus and the compression of the goiter. Under the 3D guidance, the operative resection specimen of the right lobe and isthmus was 12 ´ 7 ´ 5 cm, whereas the left lobe specimen was 12 ´ 9 ´ 6 cm. Nodular goiter and lymphocytic thyroiditis were confirmed by postoperative histopathology. There were no complications after total thyroidectomy except for non-permanent hypocalcemia and hypoparathyroidism. Our results proved that total thyroidectomy for giant goiter is challenging, and 3D image-guided thyroidectomy facilitates precise and safe resection with fewer complications. 3D CT reconstruction and 3D printing can provide anatomical details and may be considered in thyroidectomy planning for patients with giant goiter.

In Vivo Anatomical Research by 3D CT Reconstruction Determines Minimum Acromiohumeral, Coracohumeral, and Glenohumeral Distances in the Human Shoulder: Evaluation of Age and Sex Association in a Sample of the Chinese Population.

Accurate measurement of the minimum distance between bony structures of the humeral head and the acromion or coracoid helps advance a better understanding of the shoulder anatomical features. Our goal was to precisely determine the minimum acromiohumeral distance (AHD), coracohumeral distance (CHD), and glenohumeral distance (GHD) in a sample of the Chinese population as an in vivo anatomical analysis. We retrospectively included 146 patients who underwent supine computed tomography (CT) examination of the shoulder joint. The minimum AHD, CHD, and GHD values were quantitatively measured using three-dimensional (3D) CT reconstruction techniques. The correlation between minimum AHD, CHD, and GHD value and age with different sexes was evaluated using Pearson Correlation Coefficient. The mean value of minimum AHD in males was greater than that in females (male 7.62 ± 0.98 mm versus female 7.27 ± 0.86 mm, p = 0.046). The CHD among different sexes differed significantly (male 10.75 ± 2.40 mm versus female 8.76 ± 1.38 mm, p < 0.001). However, we found no statistical differences in GHD with different sexes (male 2.00 ± 0.31 mm versus female 1.96 ± 0.36 mm, p > 0.05). In terms of age correlation, a negative curve correlation existed between age and AHD among the different sexes (male R2 = 0.124, p = 0.030, female R2 = 0.112, p = 0.005). A negative linear correlation was found in CHD among the different sexes (male R2 = 0.164, p < 0.001, female R2 = 0.122, p = 0.005). There were no differences between age and minimum GHD in both sexes. The 3D CT reconstruction model can accurately measure the minimum AHD, CHD, and GHD value in vivo and is worthy of further investigation for standard clinical anatomical assessment. Aging may correlate with AHD and CHD narrowing for both sexes.

Computed tomography reconstruction based on canny edge detection algorithm for acute expansion of epidural hematoma

Backgroundand purpose: Acute enlargement of epidural hematoma often indicates a poor prognosis. This paper aims to explore the predictive value of computed tomography (CT) reconstruction based on the Canny segmentation algorithm for acute expansion of epidural hematoma. MethodsA retrospective analysis was made of 73 patients with epidural hematoma in our hospital. They were divided into two groups according to whether there was an acute expansion of hematoma during and after operation: the expansion group and the non-expansion group. Canny edge detection algorithm was used to segment the focus, and three-dimensional (3D) reconstruction was performed to predict the acute expansion of epidural hematoma. Evaluate the effect of 3D reconstruction of epidural hematoma and the application value of 3D CT reconstruction in acute hematoma enlargement. ResultsThe Dice value of the hematoma segmentation result based on Canny's edge detection algorithm was 0.919. The accuracy, sensitivity, and specificity of 3D CT reconstruction were 88.46%, 87.03, and 91.67%, respectively. ConclusionThe Canny edge detection algorithm has good accuracy in segmenting epidural hematoma, and CT reconstruction has an excellent predictive effect on the acute expansion of epidural hematoma.

Vasculature of the Nasal Cartilage Region Related to Filler Injection.

A filler injection in the nose can be essential but is also dangerous, especially in the nasal cartilage region. To safely and accurately perform a filler injection, surgeons must have detailed knowledge of nasal anatomy. Associated the vessel branches and the characteristics of different nasal regions to provide suggestions for more suitable injection sites. Fifty specimens underwent computed tomography (CT) after contrast infusion. Qualified specimens were selected for 3D CT reconstruction. Dissection was performed to confirm the accuracy of the CT data. The branches of arteries with large diameters, the dorsal nasal artery (DNA) and the lateral nasal artery (LNA) were distributed within the superficial musculoaponeurotic system layer. The DNA was seen in only 58% of specimens. The artery crossed the midline over the upper lateral cartilage in 16% of specimens. The LNA was a constant branch that traversed the nasal tip. The LNA crossed the midline to the contralateral side in 18% of patients. We divided the nasal cartilage dorsum into two regions for easy handling: the supratip region (STR) and the nasal tip region (NTR). The branches distributed in the STR mostly originated from the DNA (81.6%, 40/49), while those in the NTR mostly originated from the LNA. The vasculature of the nasal cartilage region observed in this study is similar to that observed in previous studies. However, we found that the STR was an advantageous area for filler injection. At the same time, we provided suggestions for more suitable injection methods. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Anatomical accuracy of the KODEX-EPD novel 3D mapping system of the left atrium during pulmonary vein isolation: a correlation with computer tomography imaging

Abstract Funding Acknowledgements Type of funding sources: None. Background A novel 3D mapping system (KODEX - EPD, EPD Solutions, Best, The Netherlands) enables catheter localization and real-time 3D cardiac mapping. Purpose To evaluate left atrium (LA) anatomical mapping accuracy created by the KODEX-EPD system during pulmonary vein isolation (PVI) compared with gold standard computed tomography (CT) images acquired from the same patients prior to the procedure. Methods In 15 consecutive patients who underwent PVI, 3D mapping of the LA was created on the KODEX-EPD system using the Achieve catheter. Pulmonary vein (PV), posterior wall, and appendage anatomy and diameters, were compared to the CT 3D reconstruction measured on the CARTO 3 system. Measurements were done independently by 2 physicians in each method. Linear correlation and agreement between CT and EPD measurements were assessed by Spearman correlation and Bland-Altman plot. Results Mean LA mapping time was 7.7± 3.6 min. Very high interobserver correlation was found for both EPD and CT measurements (Spearman-r=0.9). High correlation (r=0.75) was found between CT and EPD measurements. Bland-Altman plot method revealed that measurements assessed by EPD were slightly higher than those assessed by CT. Mean difference was 3.5mm, p&amp;lt;0.01. In 2 (13.5%) patients each, disagreement regarding the presence of a left common PV and a right middle accessory vein anatomy was seen. Conclusion The new KODEX-EPD mapping system allows quick and accurate mapping of the LA with high correlation to CT imaging. Some differences in left common and accessory right middle vein anatomy were seen. Central illustration: An example of the anatomy created by the KODEX- EPD system compared with the CT image of the same patient. A standard 4 vein anatomy is demonstrated by both modalities, with early branching of the right inferior pulmonary vein. A: KODEX- EPD pre-CRYO map during atrial fibrillation demonstrating connected pulmonary veins. B: 3D CT image viewed on the CARTO auto-segmentation module. C,D: KODEX- EPD posterior-anterior and PANO images post-CRYO map during sinus rhythm demonstrating pulmonary vein isolation with the same anatomy. E: Spearman correlation demonstrating a high correlation (r 0.75) between CT and KODEX-EPD measurements, p&amp;lt;0.01.

Multi-slice spiral computed tomography in diagnosing unstable pelvic fractures in elderly and effect of less invasive stabilization.

BACKGROUNDOlder people are more likely to experience pelvic fractures than younger people. Multi-slice spiral computed tomography (CT) uses three-dimensional (3D) reconstruction technology to generate 3D images that can clearly demonstrate the 3D space of fractures and detect fractures at a higher rate.AIMTo investigate the clinical value of multi-slice spiral CT 3D reconstruction in the diagnosis of unstable pelvic fractures in the elderly as well as the effect of less invasive stabilization.METHODSA total of 86 patients with unstable pelvic fractures treated between March 2016 and March 2019 underwent femoral supracondylar bone traction before surgery. Pelvic radiography and multi-row spiral CT were performed successively once the patient’s vital signs and hemodynamic indices were stable. Secondary processing of the original data was performed to obtain 3D reconstruction images and determine the vertical displacement of the pelvis. After basic or complete reduction, minimally invasive internal fixation using hollow lag screws was performed. The detection rates of fracture location and classification by X-ray and CT reconstruction were compared. Patients were divided into two groups according to the presence or absence of preoperative 3D reconstruction to compare postoperative reduction, wound healing time, fracture healing time, hospitalization time, visual analog scale (VAS) score, poor internal fixation, and functional recovery. RESULTSThe diagnostic coincidence rates of X-rays for pubic symphysis, ilium wing, sacroiliac periarticular, and sacral fractures were lower than those of CT reconstruction. The coincidence rate of CT reconstruction in the clinical classification of pelvic fractures was 100%, whereas 11 cases were misdiagnosed by X-ray; the total coincidence rate was 87.21%. The total excellent and good rates of postoperative reduction were significantly higher in the study group than in the control group (P < 0.05). The wound healing, fracture healing, and hospitalization times were significantly shorter in the study group than in the control group (P < 0.05). The VAS scores decreased in both groups postoperatively and were lower in the study group than in the control group (P < 0.05). The total incidence of poor postoperative internal fixation was significantly lower in the study group than in the control group (P < 0.05). The overall rate of postoperative functional recovery was significantly higher in the study group than in the control group (P < 0.05).CONCLUSIONMulti-slice spiral CT has high guiding significance for the diagnosis, classification, and treatment of unstable pelvic fractures in the elderly. Preoperative 3D reconstruction can effectively shorten the operation time and promote fracture healing, while minimally invasive internal fixation can effectively reduce pain and promote functional recovery of fracture sites, making it worthy of clinical application.